Originally published in the February 2008 issue of Sea Kayaker Magazine. Copied with permission of the editor. www.seakayakermag.com Cold Shock and Swimming Failure The real danger of cold water is not in the slow descent into hypothermia, but in the sudden symptoms of cold shock. by Chris Brooks

t is well known by most sea kayakers gut stitched together to form a complete tifi c community since before World War that hypothermia is a serious risk. covering that was worn by harpoon- II. These are: Getting chilled by exposure to wa- ers hunting whales from umiaks. The Cold Shock—kills in 3–5 mins. I ter even as warm as 70˚F (21˚C) danger of exposure to cold water was Swimming Failure—kills in 5–30 mins. can eventually lead to a number of se- well understood by the Arctic maritime Hypothermia—kills after 30 mins. rious and even life-threatening physical peoples. Post-Rescue Collapse—kills during or and mental symptoms. Many kayaking The Greek author Herodotus wrote hours after rescue. books focus on the various stages of about hypothermia back in 450 BC dur- The fi rst two stages of immersion— hypothermia, and while it is important ing the Persian/Greek wars comment- cold shock and swimming failure—kill to recognize them, the most serious and ing on mariners who died in sea battles more than half the people who drown. dangerous effects of cold water aren’t in the Mediterranean Sea: “Those who It’s especially important to protect your- in a slow deterioration of abilities. For could not swim perished from that cause, self from those fi rst two stages, and to do kayakers, a more realistic approach to others from cold.” The fi rst human ex- that effectively, you need to know some- the risks of cold-water immersion is to periment in cold water to test out the thing about cold-water physiology and focus on the effects that happen in the value of protective clothing, however, survival psychology. It’s also important to fi rst seconds of immersion and the fol- was not done until 1922. A doctor work- understand the denial of risk that is built lowing few minutes. ing for the Merchant Shipping Advisory into us all and causes many sea kayakers Water does not need to be drastically Committee on lifesaving appliances, to paddle without wearing protective cold to kill you. You can drown very named Dr. Hill, immersed his laboratory clothing or fail to make good plans and quickly if you are not mentally and phys- assistant, Mr. Pergarde, in 62˚F (16.6˚C) preparation prior to launching. ically prepared for sudden immersion. water and concluded: “That the cover- Up until about 50 years ago, no one Since early times, the Inuit understood ings wet or dry, protect a body from really understood the reason why peo- this danger. The waterproof paddling cooling down, and also that a rubber ple suddenly immersed in cold water jackets—tuiliqs and kamleikas—used skin outside such coverings is a further died. It was attributed to an inability by early kayakers sealed together with great protection.” to stay afl oat and vague terms such as their kayaks to provide full body cover- The four stages where death can occur “exposure.” The steady loss of lives was age. Inuit whalers even developed dry as a result of sudden cold-water immer- simply accepted as fate and an occupa- suits. They consisted of sealskin or seal sion have been recognized by the scien- tional hazard.

24 Sea Kayaker | February 2008 As long as cold shock and swimming can cause muscle spasms of the limbs attack while swimming (without a PFD) failure were considered only of academ- and chest. All of these breathing irregu- increases from 18 degrees to 24 degrees, ic interest, mariners and government larities increase the risk of drowning and on swimming failure, just prior to regulators—and later survival training if you dip underwater or have a wave drowning, the angle of your body be- schools, outdoor-sportswear manufac- splash over your face. It only takes an comes more upright at 35 degrees. turers and PFD manufacturers—concen- inhalation of about five ounces (150 ml) The drag on the body as it moves trated their efforts on protecting people of water to cause drowning. Drowning is through the water at an increasingly up- from the more protracted process of a combination of cardiac arrest and suf- right angle is increased, your stroke rate is hypothermia. As a result, hypothermia focation. Your heart stops beating within increased, and consequently your stroke is widely recognized and understood; one to two minutes after you have in- length is decreased. The cold causes in- however, even with today’s well estab- haled a significant amount of either effective swimming strokes and a poor lished teaching programs, good regula- fresh- or seawater. Water in the lungs synchronization of them to breathing. tions and much improved life-saving compromises your ability to exchange This all adds up to an exhausted swim- equipment, the two stages of immersion oxygen, and because respiratory move- mer floating nearly vertical in the water. have often been overlooked. These are ments may occur for up to five minutes As you raise your arms above the water what I want to address. when underwater, water can continue over your head to signal for help, there to be drawn into your lungs. is a further loss of buoyancy. A cry for Cold Shock Cold shock also causes a massive in- help expels air from your lungs (as much Over 15 years ago, Moulton Av- crease in heart rate and blood pressure. as four liters), removing the last vestige ery wrote an excellent article in this These cardiac responses may cause of buoyancy keeping your mouth above magazine (“Cold Shock,” SK, Spring death, particularly in older, less healthy the water. The result is that you sink be- ’91), noting that “immersion in cold people. neath the waves and never resurface. water kills more sea kayakers than any The intense effects of cold shock last While swimming failure doesn’t apply other factor in our sport.” Cold shock two to three minutes and will settle directly to kayakers who maintain con- has been observed in people sensi- down after about five minutes of immer- tact with the kayak after a wet exit, the tive to cold at water temperatures as sion. This period of involuntary reactions “failure” is just a manifestation of physi- high as 77˚F (25˚C). In water below is just at the critical stage of sorting your- cal symptoms that do apply. Swimming 60˚F (15˚C), the effects of immersion self out after your kayak has flipped and failure will manifest itself in compromis- become significantly life-threatening you’re working to adjust to the wind and ing whatever physical tasks you need to to everyone. The lower the temperature, waves and avoid inhalation of water. do: holding onto the kayak, setting up the more severe the symptoms. The a paddle-float outrigger, lunging onto effects of cold shock are completely out Swimming Failure your back deck and so on. Within a few of your conscious control. If you don’t Swimming failure is caused by rapid minutes after immersion, you get a cold- protect yourself from cold water, they cooling of the muscles and nerves and induced anesthesia that causes a discon- will happen to you whether you like it can kill within about 5–30 minutes after nect between your brain and your limbs or not. If you really don’t believe that it immersion. It is much more common and their position in the water—you will affect you, the next time you take a than you’d think. It’s often poorly diag- don’t know where your arms are. Your shower, turn the cold water on full blast nosed by investigators because it usually fingers grow numb and paralyzed, so and aim it at your belly button. You will isn’t possible to delve into the precise your fine motor skills deteriorate. Grip soon be a believer. history of what happens to a victim strength is reduced, and cramps disable immediately after immersion. The cause your limbs. Shivering further impairs Cold shock is caused by rapid skin of death listed on the death certificate is movement, and panic compromises cooling and can kill within three to five commonly reported as drowning. To be mental functions. minutes after immersion. On initial im- sure, drowning follows the inhalation mersion, you make a huge inspiratory of water, but it is swimming failure that The Psychology of Survival gasp. Being immersed in near-freezing leads to drowning when the mouth and Survival schools have only recently cold water is also extremely painful, and nose can no longer be kept above the started teaching lifesaving survival psy- the sudden sensation of acute pain can surface and slip underwater. chology. It’s as important to know about accentuate the inspiratory gasp. The gasp the psychology of survival as it is to is followed by severe hyperventilation: a It’s very dangerous to swim in cold know about cold-water physiology. The fourfold increase in your breathing rate. water, and it doesn’t need to be that cold work in this field has been pioneered It is not uncommon for you to be pant- (just 60˚F) to cause a swimming failure by Professor John Leach, of Lancaster ing at a breathing rate of up to 65 times that will drown you. Newspaper reports University, in the U.K. a minute in this critical stage, so there is about drownings often mention that the The brain usually manages to function no chance to hold your breath. Indeed, victim was “an outstanding swimmer, yet very successfully even in a whirlwind in water below 60˚F, your breath-hold- he only swam 50 yards and drowned.” environment. What psychologists refer ing ability is reduced by 25–50 percent. Your swimming ability in warm water to as “human information processing” is If the water is near freezing, even after bears no relationship to your swimming capable of handling a lot of decisions in the effects of cold shock have settled, ability in cold water. Professor Mike quick fashion. Unfortunately, however, you’ll only be able to hold your breath Tipton of the University of Portsmouth, in life-threatening situations, our brain for about 12–17 seconds. U.K., and his colleagues in Sweden dem- is very limited in its ability to process The rapid breathing rate on its own onstrated quite clearly that your angle of information and to respond quickly and

February 2008 | Sea Kayaker 25 correctly. the emergency. If no schema is present, nism that “shields” us from some of the Our brain uses an input selector (also a plan of action has to be formulated stresses in life but sometimes doesn’t called a “register”) to process all the in- using working memory alone. That’s a do as good a job as it should do. This formation received by our sensory or- very time-consuming process and has a is called self-denial. When kayaking gans. All the sensations, such as vision, limit on how much information it can accidents make the news, it’s often the hearing, taste, smell, temperature, vi- hold and process in a given time. same story: Paddlers didn’t dress for bration, pain and posture, are constantly With each new situation, a schema is the water and weren’t prepared for being fed into this register or input selec- developed and a response is generated. the weather. With the risks so eas- tor by nervous system “telephone lines.” This response is then stored in long- ily perceived, why did these kayakers Here the information is encoded and put term memory for a more rapid future ignore the clear threat to their lives? into a central processing unit, which is response. Professor Leach has an explanation for your short-term or working memory. As we go through life, experiences this. If your life is routinely comfortable The number of “telephone lines” to the from the benign to the dangerous are and uneventful, your perception of a central processing unit is very limited, entered into our long-term memory as threat may be minimized by a feeling and in any survival situation, you should separate schemas. We have millions of of having the odds in your favor—“It assume that you only have one line. This schemas logged into our brain. Most will never happen to me.” The response makes the processing system essentially are quite ordinary and automatic: turn- to an imminent threat is generally, and a single-channel analyzer. This explains, ing the alarm clock on before you go to surprisingly, one of inactivity and a for instance, why people will swear that sleep at night, locating your toothbrush failure to take any positive protective they did not hear an alarm sound when and brushing your teeth first thing in action. they were completely engaged in some the morning, unlocking the car and put- People tend to reduce their aware- other complex task, even if the alarm ting the keys in the ignition and so on. ness of personal threat to a level that was very loud. They will be telling the Some, like defensive driving techniques, they feel comfortable with. They will truth because their internal “telephone fire drills, CPR and kayak rescues, are also ally themselves with other people lines” were busy processing the other all created as schemas and reinforced by in their group who appear similarly un- information and could not process any regular practice. If there is no rehearsal concerned about the threat. A consen- more information. of these emergency schemas to get them sus that something is not a serious risk The limitation of the input selector is fully established in long-term memory, produces a strong desire to conform to one of the primary reasons it’s not easy then the fine detail in them fades, and the group. This failure to acknowledge a for a single person to deal with a complex it’s not remembered for later use when risk is often made worse because prepa- problem on his/her own under emer- it may be lifesaving. That is why critical ration for dealing with a threat is often gency conditions, and why working as a skills in our daily work and play require considered to be boring, inconvenient team provides a much better chance of regular refresher training. and costly. survival. Commercial airlines have rec- This process of decision making in nor- Kayaking in water under 60˚F is po- ognized this limitation and have intro- mal, nonstressful circumstances takes tentially very dangerous, and if you duced cockpit resource management for about a tenth of a second to happen. If don’t make the appropriate plans and their flight crews to share in the decision- no schema has been developed for such preparations, it constitutes taking a very making process once borne solely by the ordinary situations, then the informa- serious risk. captain. Kayakers should also adopt this tion processing is done by the super- approach of sharing the responsibilities visory attentional system (SAS) in the Know Your Enemy required by emergency situations. Any brain. The SAS takes care of planning, You must dress according to the water rescue or capsize recovery should be a decision making, troubleshooting, error temperature, not according to the air group effort. The person who capsized correction and solving novel problems. temperature. What you are wearing is likely to be under the greatest stress It also helps us perform in technically at the time of immersion is critical. If and the most likely to overlook protocols difficult or dangerous environments and it is not on you or if it’s not zipped up and to take inappropriate actions toward overcome strong habitual responses. and ready for the water, it won’t do the recovery. Kayakers who aren’t directly The SAS kicks in when we need to re- job you need it to do. If you wind up assisting with a reentry can monitor drift spond to an unplanned capsize, decide in the water, your immediate enemy or traffic, gather other members of the whether to swim to shore or wait to be is not hypothermia but drowning. group, look for places to go ashore, etc. rescued or assist an injured buddy crying Respiratory distress leading to water From the brain’s input selector, infor- for help. However, under stress and with inhalation is most likely in the first mation is entered into the short-term or no schema to follow, the SAS is slow and few minutes of exposure to cold water working memory where it is compared takes 100 times longer to process infor- and occurs well ahead of any symp- with other similar experiences that may mation compared to information stored toms of hypothermia. If you are well already have been encoded in long- as normal schemas. In an emergency, it protected from the cold, the symptoms term memory as schemas or routines. can be quickly saturated with informa- of cold shock should be minimal. If The stored schemas—routines that have tion and, as a result, be disabled just you experience any of its symptoms, been learned and reinforced by prac- when it is most needed. your objective for the first 30 seconds tice—are available for comparison to to three minutes is to keep your nose any new information entering into the Self-Denial and mouth out of the water. In those working memory. The connection with Going hand in hand with our human first few minutes, you should be very the schema provides a quick path to de- information processing system, we also cautious about making decisions about ciding upon an appropriate response to have a psychological protective mecha- what course of action to take.

26 Sea Kayaker | February 2008 Precautions portant immediately after a capsize and often you practice each technique in safe You can avoid paddling in cold water, wet exit because it helps you keep your but realistic conditions, the more effec- but for most sea kayakers this is not mouth above water while your breath- tive and reliable that particular schema really an option. Just remember: Once ing is erratic. The Canadian Red Cross will be when you need to resort to it in you start paddling in water 60˚F or has reported that 88 percent of canoe- an emergency. lower, you have entered the danger related drowning victims and 67 percent zone. of kayak-related drowning victims in Chris Brooks is a physician, scientist and You can, in fact, acclimatize yourself to the last 10 years were not wearing PFDs. inventor. He is the director of R&D at Sur- the cold water by taking daily cold show- Wear the best-performing PFD or life vival Systems Ltd. Dartmouth, Nova Scotia, ers for about three weeks, which will re- jacket you can fi nd. Make sure that it Canada, and is an adjunct professor in the duce the symptoms of cold shock for up fi ts well enough to keep from riding up faculty of health and human performance at to about one year. For some kayakers, when you are in the water. If you can’t Dalhousie University, Halifax, Nova Scotia. that may be part of preparing for cold get the waist belt to cinch up under your Chris wrote the report Survival in Cold water. It is interesting to note that pris- rib cage, add a crotch strap to the PFD. Water—Staying Alive in 2003 for the Ma- oners at Alcatraz were allowed to take Immersion clothing ranging from rine Safety Directorate of Transport Canada. only hot showers. By eliminating the neoprene wetsuits to full dry suits will possibility of acclimating to cold water, be needed depending on the trip. A neo- Recommended reading: Essentials of Sea the prisoners were prevented from being prene cap will offer a useful measure of Survival, by Frank Golden and Michael J. Tipton able to prepare for a swim to escape. protection—a full hood even more, as it (Human Kinetics, 2002); Survival Psychology, by Be prepared for the effects of cold protects neck and ears. If you get too hot, John Leach (Macmillan Press, 1994). shock when you capsize. Hold onto your you can always splash water on yourself kayak for support until you can control and make use of evaporative cooling. your breathing before attempting a self- Practice capsizes regularly, starting in rescue or assisted rescue. You don’t want warmer water, then—with caution and to risk having your head get submerged very close to shore with a buddy, if not if you can’t hold your breath. a group of kayakers—repeat the exercise Always wear a fl otation device. The in colder water. Practice a broad range of buoyancy it provides is especially im- capsize recovery techniques. The more

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February 2008 | Sea Kayaker 27